EGR Deletes - Is it worth it?

Last Modified : Mar 30, 2021

The topic of deleting someone's EGR system has be brought up to me several times.  Especially with the 6.0L diesel crowd. I thought I would talk a little about what some of the advantages and disadvantages of deleting the EGR coolers on the 6.0L Powerstroke, the 6.4L Powerstroke, and the 6.7L Powerstroke.

The first thing you might say is... how can all the advantages and disadvantages of deleting the EGR apply to all these Powerstroke engines?  The math is easy.  The EGR system is easy.  The whole purpose of the EGR system on ANY vehicle, gas or diesel, is to reduce the emission of NoX.  That is Nitrites of Oxide.  NoX is really bad for the environment, but we won't go into why it is.  Just trust me, it is bad.

You see, we never had as big of a problem in the old days of producing huge amounts of NoX.  When fuel economy, efficiency, and technology were lacking we weren't able to create the ideal environment for the formulation of Nox. It is produced in multiple ways, but one way is the exposure to extreme temperatures.  The effect is multiplied when combined with preheated air flow (ahem, air compressors create heat, turbos are air compressors...).

EGR systems were brought about to reduce combustion chamber temperatures. Yes, you heard that right.  Using hot exhaust gas injected through the intake will reduce combustion temperatures.  Exhaust gas is practically inert - that means there is nothing left physically to burn - no oxygen and very little fuel.  When it is forced into the intake of the engine, it becomes a filler reducing the amount of oxygen that can enter the chamber through the valves.  This lack of oxygen causes a less powerful explosion upon combustion thereby reducing engine efficiency and reducing combustion temperatures.  The PCM uses a EGR valve to control flow of the exhaust through the intake so it can manage when and how much exhaust gas is recycled.  Because of the use of the valve, the PCM limits or eliminates all EGR flow during periods of high demand from the engine (such as your lead foot.)  EGR coolers come in to play by reducing the exhaust gas temperature further before allowing it into the engine.

So what you have learned today is that EGR coolers reduce NoX, reduce combustion temperatures, and reduce engine efficiency ONLY when commanded by the PCM?  Sounds like you should leave the EGR system and the cooler intact to me.  The 6.0L were know for EGR cooler failures.  Ultimately, it was a poor design that ruptured due to oil cooler failure.  There was a term dubbed "bulletproofing" your 6.0L.  Its really a broadly mistaken term these days.  It is actually a brand name. The brand Bulletproof sells updated FICMs, EGR deletes, Perfromance EGR coolers, ect...

The EGR coolers were originally made with a finned design similar to a radiator or heater core.  Many companies now produce the updated EGR coolers with much better solid tube design, even Dorman makes a better EGR cooler, Dorman 904-262.

This is all just food for thought.